Subscribe free to our newsletters via your
. 24/7 Space News .




NANO TECH
Never say never in the nano-world
by Staff Writers
Vienna, Austria (SPX) Apr 03, 2014


This is an artistic impression of the nanoparticle in a laser trap. Image courtesy Inaki Gonzalez and Jan Gieseler.

Objects with sizes in the nanometer range, such as the molecular building blocks of living cells or nanotechnological devices, are continuously exposed to random collisions with surrounding molecules. In such fluctuating environments the fundamental laws of thermodynamics that govern our macroscopic world need to be rewritten.

An international team of researchers from Barcelona, Zurich and Vienna found that a nanoparticle trapped with laser light temporarily violates the famous second law of thermodynamics, something that is impossible on human time and length scale. They report about their results in the latest issue of the prestigious scientific journal Nature Nanotechnology.

Surprises at the nanoscale
Watching a movie played in reverse often makes us laugh because unexpected and mysterious things seem to happen: glass shards lying on the floor slowly start to move towards each other, magically assemble and suddenly an intact glass jumps on the table where it gently gets to a halt. Or snow starts to from a water puddle in the sun, steadily growing until an entire snowman appears as if molded by an invisible hand.

When we see such scenes, we immediately realize that according to our everyday experience something is out of the ordinary. Indeed, there are many processes in nature that can never be reversed. The physical law that captures this behavior is the celebrated second law of thermodynamics, which posits that the entropy of a system - a measure for the disorder of a system - never decreases spontaneously, thus favoring disorder (high entropy) over order (low entropy).

However, when we zoom into the microscopic world of atoms and molecules, this law softens up and looses its absolute strictness. Indeed, at the nanoscale the second law can be fleetingly violated.

On rare occasions, one may observe events that never happen on the macroscopic scale such as, for example heat transfer from cold to hot which is unheard of in our daily lives. Although on average the second law of thermodynamics remains valid even in nanoscale systems, scientists are intrigued by these rare events and are investigating the meaning of irreversibility at the nanoscale.

Nanoparticles in laser traps
Recently, a team of physicists of the University of Vienna, the Institute of Photonic Sciences in Barcelona and the Swiss Federal Institute of Technology in Zurich succeeded in accurately predicting the likelihood of events transiently violating the second law of thermodynamics.

They immediately put the mathematical fluctuation theorem they derived to the test using a tiny glass sphere with a diameter of less than 100 nm levitated in a trap of laser light. Their experimental set-up allowed the research team to capture the nano-sphere and hold it in place, and, furthermore, to measure its position in all three spatial directions with exquisite precision.

In the trap, the nano-sphere rattles around due to collisions with surrounding gas molecules. By a clever manipulation of the laser trap the scientists cooled the nano-sphere below the temperature of the surrounding gas and, thereby, put it into a non-equilibrium state. They then turned off the cooling and watched the particle relaxing to the higher temperature through energy transfer from the gas molecules.

The researchers observed that the tiny glass sphere sometimes, although rarely, does not behave as one would expect according to the second law: the nano-sphere effectively releases heat to the hotter surroundings rather than absorbing the heat. The theory derived by the researchers to analyze the experiment confirms the emerging picture on the limitations of the second law on the nanoscale.

Nanomachines out of equilibrium
The experimental and theoretical framework presented by the international research team in the renowned scientific journal Nature Nanotechnology has a wide range of applications. Objects with sizes in the nanometer range, such as the molecular building blocks of living cells or nanotechnological devices, are continuously exposed to a random buffeting due to the thermal motion of the molecules around them.

As miniaturization proceeds to smaller and smaller scales nanomachines will experience increasingly random conditions. Further studies will be carried out to illuminate the fundamental physics of nanoscale systems out of equilibrium. The planned research will be fundamental to help us understand how nanomachines perform under these fluctuating conditions.

Original publication in Nature Nanotechnology: Dynamic Relaxation of a Levitated Nanoparticle from a Non-Equilibrium Steady State. Jan Gieseler, Romain Quidant, Christoph Dellago, and Lukas Novotny. Nature Nanotechnology AOP, February 28, 2014. DOI: 10.1038/NNANO.2014.40

.


Related Links
University of Vienna
Nano Technology News From SpaceMart.com
Computer Chip Architecture, Technology and Manufacture






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





NANO TECH
Fabricating Nanostructures with Silk Could Make Clean Rooms Green Rooms
Somerville MA (SPX) Apr 01, 2014
Tufts University engineers have demonstrated that it is possible to generate nanostructures from silk in an environmentally friendly process that uses water as a developing agent and standard fabrication techniques. This approach provides a green alternative to the toxic materials commonly used in nanofabrication while delivering fabrication quality comparable to conventional synthetic polymers. ... read more


NANO TECH
Misleading mineral may have resulted in overestimate of water in moon

Land a Lunar Laser Reflector Now!

Scientists date Moon at 4.470 billion years

New research finds 'geologic clock' that helps determine moon's age

NANO TECH
Health risks of Mars mission would exceed NASA limits

Mars and Earth move closer together this month

The Opposition of Mars

Mars yard ready for Red Planet rover

NANO TECH
NASA Commercial Crew Partners Complete Space System Milestones

Using ethic frameworks for decisions about health standards on long duration spaceflights

NASA suspends Russia ties, except on space station

China, Asia-Pacific, will power world tourism: survey

NANO TECH
China launches experimental satellite

Tiangong's New Mission

"Space Odyssey": China's aspiration in future space exploration

China to launch first "space shuttle bus" this year

NANO TECH
Soyuz Docking Delayed Till Thursday as Station Crew Adjusts Schedule

US, Russian astronauts take new trajectory to dock the ISS

Software glitch most probable cause of Soyuz TMA-12 taking two day approach

Russian spacecraft brings three-man crew to ISS after two-day delay

NANO TECH
Soyuz ready for Sentinel-1A satellite launch

Boeing wins contract to design DARPA Airborne Satellite Launch

EUTELSAT 3B Mission Status Update

Arianespace's seventh Soyuz mission from French Guiana is readied for liftoff next week

NANO TECH
Lick's Automated Planet Finder: First robotic telescope for planet hunters

Space Sunflower May Help Snap Pictures of Planets

NRL Researchers Detect Water Around a Hot Jupiter

UK joins the planet hunt with Europe's PLATO mission

NANO TECH
The Space Debris Radar Developed By Indra Passes ESA Tests

Chile quake pushes copper price to three-week high

Space Observation Optics Cover from IR to X-ray Wavelengths

Intel bets big on cloud, with stake in Cloudera




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.